Sound Designing with Flowing Water

Water’s vacillating voice, from mountain top to ocean destiny, echoes our own passage through life. Birthed as a murmur. Growing to babbling infancy and boisterous youth. Maturing, sometimes to tumultuous mid-life crises with sudden falls. Then settling into a quiet, meandering old age before its own inescapable end, reunion with the sea. The secret of mastering sound design with flowing water is to allow water tell your story.

What is your story?

Is your story wild, and impulsive? Then select first and second order stream sounds, which are the youngest stages (see How to Record Flowing Water for discussion of stream orders). Is your story deeply woven and sophisticated? Then echo it with the highest stream orders, and at times, use only a few currents emanating from the river edge, if any flowing water sounds at all.

Mismatch water’s voice with the story being told and you’ll mistakenly employ a young boy’s voice to tell an old man’s story. To achieve a harmonious match, you have to really know your flows.

To expand your knowledge as a sound designer you might follow a river from headwaters to mouth, listening all the while. Unfortunately, this will be a distance of hundreds, if not thousands, of miles for a higher order flow, such as the Yukon, Columbia, or Mississippi River. And even if you were to pursue this rare opportunity, you’ll likely be brought up short by a series of voice-gagging dams. It is possible, however, to draw valuable lessons from generally undammed upper river systems.

Case Study: Upper Merced River

Let’s follow the changing voice of the Merced River from its origins on the side of Mt. Lyle until it plunges over Vernal Falls into Yosemite Valley, a descent of more than 6,000 feet and a distance of approximately 15 miles. I took this journey in 1994 to record and produce the album Song of the Merced River. In the map above we see my path, which starts on the right and travels directly west. Below it is the resulting wave form of the assembled sound recordings that correspond to the map. The more the blue dominates the graph, the louder the sound.

By viewing the two images simultaneously, it’s apparent that a river has many voices.

Voices

So where do you go to find the very beginning of a river? The word ‘headwaters’ is plural for a reason. Does the river start where a spring emerges into a bubbling, chirping pool? Or does it start at a higher elevation on the edges of a snowfield, with drips of meltwater tapping reggae beats before they combine to form a rivulet? The first utterance of an infant giant is for all practical purposes what you hear at the point that you cease your search. Those bubbles or tapping droplets will soon lead you, always along the path of least resistance, to a first order stream, whose flow etches the landscape. When a first order stream is joined by another first order stream, a second order stream is born. The flow builds in order rating through the watershed. When a river ceases to exist, either by confluence into a larger river or by emptying into the sea, for example, it has achieved its highest order. The Ohio River is an 8 and the Mississippi a 10.

It’s important to note that flowing water is most expressive at the lower orders. Sometimes just a splatter, as when a narrow rill takes a fall onto flat rock, or maybe a hollow gurgle when a stream curls into a tiny, root cavity pool. The small scale clarifies the voice, because only one sound-producing event occurs at a time.

As it widens and grows, the stream will feature more than one sound producing event at any given time; a soundscape, albeit, in miniature. You can hear a splatter, a gurgle, sloshing, and perhaps babbling, all at the same time.

The streambed stones are the notes. They offer the key to finding the right voice in a sound library to match the setting of your sound design. The different shapes and sizes of the stones, combined with the width and slope of the stream, provide all the information you need to correctly match the “voice” to the story.

On high elevation streams, the stones begin as large and jagged, fresh chards of a mountain. They gradually get smaller and more rounded as you progress downstream. Though hard to detect over short distances, over several miles this becomes obvious, provided that the area has not been subject to glaciation. Take photos along the way and you’ll see the difference.

Initially, the water sounds rough and crude to my ears, and full of splashes and sprays because the slope is steep, the rocks flat and angular. Further downstream from the source, the rocks have been fragmented into smaller pieces and are now small enough to be pushed aside by the stream during heavy flow rates. The path of least resistance has eased and the sound takes on smoother, more rolling notes. In this way a stream may be said to tune itself. (More about this in How to Record Streams.)

Yosemite National Park, home of the Merced River, is the result of dramatic geologic uplift and glacial carving, so the slope and riverbed topography change often and sometimes dramatically. Rushing rapids, then a placid lake, then a booming waterfall, then a nearly silent meander. Some 10,000 years ago, glaciers grinding against the granite bedrock and then melting into torrents rounded many of the boulders. The rounded boulders themselves were rearranged by the great earthquake of 1872, tuning the river yet again. Muir notes in The Earthquake, “As soon as these rock avalanches fell every stream began to sing new songs.”

Cycles

In many river systems there is often a natural cycle of high and low water that corresponds with the changing wet and dry seasons. There may also be floods, particularly where the upper watershed has been deforested, reducing the area’s natural water retention capability. In determining flow rates, a sound designer should consider the river’s source, the season, time of day, and the health of the watershed. For example, if the source of a river is melting snow, then a typical daily cycle in the summer would be lowest water flow in the morning and highest water flow in the late afternoon and evening. On the Hoh River in Washington State this difference in August can spell a difference of several inches in water height, exposing or submerging several lateral feet of stones (the notes) onshore. On the Hoh there is also a seasonal cycle--the river low in summer when rainfall is least; high during the rainy winter season; and highest during the spring, when the combined impact of snow and rain combine cause flooding. Though rare, these floods stir up a raucous underwater symphony as stones and branches bump and crash and even larger boulders and uprooted trees boom and bang along the river bottom. (These sound files are included in Flowing Water).

In areas deforested by logging or wildfire the normal water retention of the land is substantially reduced. Rivers which had previously flowed all year are now destabilized by drought and flood, causing a disruption of the stones and the resulting de-tuning of the sound back to earlier, younger stream conditions.

Effects on Wildlife

Just as we would have to stand closer and speak louder if we were to have a conversation next to a large waterfall or rushing stream, many forms of wildlife experience difficulty communicating near a loud flow of water. Water sounds can reduce the intelligibility of messages sent by many species, especially birds. But even more importantly, for animals that rely on their keen listening skills to survive, loud water sounds can inhibit their ability to detect the soft, measured sound of an approaching predator. You’ll see a doe that dares to drink from a mountain stream compensating for the temporary loss of sentinel hearing with more frequent glances in every direction. She’ll then drink quickly and depart. Some bird species, such as the American Dipper, have adapted their communications to perform well in noisy situations, using both frequency and amplitude modulation in their calls.

Consider too, that it’s not just water that drains down river valleys. So does cold air, particularly in the mornings. And, if the conditions are right, warm air will flow up the valley in the afternoons and early evening. These alternating flows have two consequences. First, the stream and its environs will experience greater fluctuations in temperature and wind--both unfavorable to sound propagation. And secondly, winged insects know to use these daily cycles of wind direction as a commuter line up or down the valley. You’ll need to remember as a sound designer to reduce sound clarity in river areas because of these tide-like winds. You’ll also want to include possible close fly-bys of winged insects for sensational accents. The sounds of wildlife, including insects, will be discussed more completely in Sound Designing with Riparian Zones.

Summary

In a nutshell: Get familiar with the many age-related voices of water, then pick the appropriate voice or voices to tell your story.